Substrate processing systems using radio frequency (RF) generated plasmas, require a return path of RF currents generated during processing back to a source, such as the RF source that supplied the current. In some embodiments, the return path may include the current traveling through a substrate support along a floor of the processing system and then ultimately along a wall of the processing system back to the source. However, the inventors have discovered, that when operating under certain processing conditions, arcing between chamber components, such as between the substrate support and adjacent chamber components, and/or stray plasma can undesirably occur, leading to component damage and/or generation of particles that can further undesirably contaminate a substrate disposed in the processing system.
Accordingly, the inventors have provided embodiments of improved substrate supports for use in substrate processing systems.